نوع مقاله : مقاله پژوهشی
نویسندگان
1 دانشجوی کارشناسی ارشد، دانشگاه تربیت دبیر شهید رجایی، تهران، ایران
2 دانشیار، دانشگاه تربیت دبیر شهید رجایی، تهران، ایران
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Ultrasound contrast agents or UCAs are microbubbles with a biocompatible shell that increase the resolution of the ultrasound image when injected into the blood. Lipid shedding in UCAs refers to the process of lipid separation from the microbubble shell under ultrasound field stimulation. In this paper, it is shown by dimensional analysis that diffusion phenomena are negligible on the time scales that characterize a typical ultrasonic pulse. Then, using MATLAB software, a modified Rayleigh Plesset equation was solved numerically, which describes both the mechanism of lipid loss and the characteristics of the lipid shell. The results shows that the microbubbles eventually reach a constant equilibrium radius due to shell shedding after successive excitation pulses and this phenomenon causes a significant decrease in the intensity of the frequency response components emitted from them. Also, by increasing the excitation frequency, in the same pressure amplitude , the rate of shell shedding decreases.
کلیدواژهها [English]
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